DarkOrca, I was thinkning of something akin to the Limit bar from FF7 where the more damage you take the more the bar fills up, when its filled you can use a limit break. Or like FF8 when you had to be in critical health and/or under the status effect of Aura.
trying to think of a Botany secondary LB/OD but does Dark Harvest sound like something for DoL or DoW/M